1. Field of the Invention
The present invention relates to a transmission control system in an electric vehicle in which a battery is used as an energy source for a motor and is charged with electric power generated by the motor by regenerative braking of a driving wheel connected to the motor through a transmission.
2. Description of the Prior Art
There are conventionally known transmission control systems in vehicles driven to travel by an electric motor using a battery as an energy source, in which the battery is charged with an electric power generated by the motor through regenerative braking of driving wheels, thereby prolonging the possible travel distance of the vehicle obtained by one charging (for example, see Japanese Patent Publication No. 6204/81 and U.S. Pat. No.3,621,929).
The magnitude of a regenerative energy provided by a regenerating braking varies depending upon a transmission ratio of a transmission mounted between the driving wheels and the motor. In the vehicles described in the above prior art references, however, the transmission ratio cannot arbitrarily be changed and hence, the kinetic energy of the vehicle cannot be recovered as regenerative energy without any waste, to effectively charge the battery.